You read correctly. Dell will start charging customers up to $50 for factory-installed Windows XP on some of their PCs, Computerworld reports today.

Consumers interested in the bargain-basement Vostro line of desktops and notebooks will pay $20 to $50 more for Windows XP Professional installed as a "downgrade" from Windows Vista Business or Vista Ultimate than they would for just Vista.

To meet Microsoft's June 30 end-of-availability deadline, Dell will stop pre-installing most versions of XP after tomorrow. Yet it will still be able to ship PCs with XP by taking advantage of the downgrade rights built into Vista Business and Vista Ultimate. Downgrading lets Dell install Windows XP Professional in lieu of Vista -- though the newer operating system is still shipped with the machine so that buyers can, if or when they want, transition from XP to Vista.

The full details, below:

Adding Vista Business to a Vostro 1000 notebook, for example, costs an additional $99 above the price with the default operating system, Vista Home Basic. However, selecting the downgrade option -- Windows XP pre-installed and Vista Business installation media in the box -- costs $149. That's a $50 downgrade surcharge.

Downgrading from Vista Ultimate comes with a smaller add-on charge, although the Vista operating system selection itself is pricier. Adding Vista Ultimate to a Vostro 400 desktop, for instance, costs $149 more than the default Vista Home Basic; choosing to downgrade from Ultimate -- Windows XP pre-installed and the Vista Ultimate installation disc in the box -- costs $169, a surcharge of $20.

On its consumer PC site, Dell doesn't specify whether it is slapping downgrade fees on three systems that can be configured with XP: the 630 and 720 H2C desktops and the M1730 notebook, all of which are part of Dell's XPS high-end line. Dell has said that it will not offer downgrades for any "currently available Inspiron laptops and desktops." Inspiron is Dell's best-selling consumer brand name.

Dell did not respond to a call asking for more information about downgrade charges for its consumer PCs.

What do you think, readers? Would you pony up for XP or settle for Vista? (Or drop the whole thing and get a Mac?) Tell us in TalkBack.